All plans use mm exclusively. Airport blueprints, for example, are in mm. At first blush it seems excessive, but it makes sense from a consistency & accuracy POV - 6.096m takes up 2 more characters than 6096 - they don’t even need to specify the units “mm”, because it is assumed, and anything else introduces room for error.
Discord is OK for real-time chat or VC, but is awful for forum-like discussions. Comment-specific context is lost in the single-threaded noise and search is borderline useless. The true forum-designed format of Lemmy, Reddit, and predecessors is far and away better. In my opinion Twitter - the legacy, ubiquity and tech - would be a better forum than Discord. That was hard to type and I need to quickly bleach my fingers.